There's a category of engineering problem I find genuinely interesting: systems where the cost of getting consistency wrong is immediate, measurable, and financial rather than just "a bug to fix later." Trading data pipelines sit squarely in that category.
Read this breakdown of how trading systems handle data consistency across multiple sources, and it surfaced a few things worth sharing.
Conflict Resolution Needs a Consistent Rule, Not a Smart One
The article makes a point I think is underappreciated: when two data sources disagree, the most important property of your conflict resolution logic isn't that it's correct in some absolute sense — it's that it's consistent and predictable.
In most trading contexts, you can't know with certainty which source has the "true" price at any given moment. What you can do is establish a clear rule (most recent timestamp wins, source A is authoritative for this instrument, etc.) and apply it without exception. Inconsistent conflict resolution — where the system sometimes picks one source, sometimes another, based on factors that aren't fully specified — is worse than a simple rule that's occasionally wrong, because at least a simple rule is debuggable.
